Until about twenty-five years ago, treatment of polyps in internal organs, the colon for example, involved cutting through the abdominal wall, resecting an area of the colon and keeping the patient in the hospital until recovery from this major surgery. The only exceptions were polyps that were near the anus. After fiber optic filaments were invented, first diagnosis, and then treatment, was by the colonoscope. Colonoscopic polypectomy was introduced in 1969 and is considered relatively effective with a morbidity rate at present of 1% to 2.3% and a mortality rate of 0.01%. At present, the state of the art is to bite or snare the stalk of the polyp which crushes the tissue. After the physician decides that the tissue will not bleed significantly, he or she simply squeezes the forceps or snare further and pulls the specimen out. If the physician decides the tissue may bleed significantly, then an electrosurgical cautery unit provides a "coagulation" current. In actual fact, the current cauterizes all tissue, but coagulation does take place also.
Complications include bleeding, either immediately after the stalk is transected, or within twenty-four hours as crushed tissue moves, or a delayed hemorrhage up to two weeks after the cauterized eschar separates from the colonic wall. Accidental perforation of the colon occurs less frequently, but still up to 1% of the time. When colonic perforation does occur, it is usually results from the electrocautery. This can result from the electricity going via the blood vessels to the base of the polyp and the wall of the colon, the polyp head contacting the surrounding tissue, the cautery current being transmitted by a pool of fluid, the cautery current going through the head of the polyp to the opposite wall, the active electrode touching the surrounding tissue, and a pool of liquid reaching the metal inside the instrument, and so shorting out through the colonic wall. Also, the electrocautery current can short out through the patient or the endoscopist. Also perforation may be silent. A "post-polypectomy coagulation syndrome" almost certainly represents injury through the wall with micro-perforation. Actually, electrocautery is dangerous and in most hospitals is restricted to trained endoscopists who guard their privileges.
Other complications occurring during polypectomy include snare entrapment where the snare can neither be closed to transect the polyp nor opened to withdraw the snare. The snare and sheath may be left in place protruding from the rectum. Usually in one to three days, the snare can be disengaged without too much difficulty. The patients' comments about this complication are not well documented in the surgical literature.
Another complication is the lost polyp. The smaller polyp can be lost more easily and is harder to find. If the polyp is not found, one cannot simply wait for the patients to pass it with their stools. The polyp will autodigest, and become unsuitable for diagnostic purposes.
Perhaps the most frequent complication of the electrocautery is destruction of the tissue near the snare. The purpose of removing the polyp is to see if it is malignant. If the malignancy has invaded the stalk, one wants to know if all the cancer was removed during the procedure. Electrocautery usually makes exam by pathologists quite limited.
In addition, no list of complications would be complete without mentioning the infrequent, but always spectacular, explosions from a spark during the electrocauterization procedure. This event is a rather popular subject in surgical literature.
Another major complication is that often neither the endoscopist, the radiologist, or the surgeon, know exactly where the polyp was. The bowel both telescopes and stretches over the colonoscope so that measuring distances from the anal verge to the polyp using the colonoscope is notoriously inaccurate. Barium enemas are also inaccurate. The wall of the colon is made up of muscles and elastic tissue stretching and contracting all the time. Physicians have no way at the present time of precisely measuring exactly where a polyp is. The only exceptions are if it is very close to landmarks like the anal verge, appendix, splenic flexure, or hepatic flexure of the colon. The state of the art is for the surgeon to remove a segment of the colon which hopefully will include the polyp stalk. The colon segment is opened after it is removed, and an attempt is made to locate the stalk of the polyp. If the stalk is not located, then the surgeon either resects more colon with all the potential complications of doing this, or closes the abdominal wall and hopes the lost stalk of the polyp is really in the specimen and not in the patient.
In summary, endoscopic polypectomy is an inherently risky and intrinsically dangerous procedure which is made acceptable and relatively safe by skilled endoscopists.
Procedures for treating bleeding polyp stumps are known. In The Surgical Clinics of North America, December 1989, Dr. Kenneth Forde states that the bleeding polyp stump can be sprayed with iced saline or dilute epinephrine solution through a cannula in a colonoscope. However, commercially available colonscopes are only 168 centimeters long, roughly six feet, so that the cannula would have to be longer, and such cannulas are not available. In addition, undue difficulty would be encountered in pushing a solution down a narrow column that long.
One technique for identifying a polyp stalk location during colonic resection is to first mark the stalk internally with a liquid dye or ink. The dye or ink will be transported to the colon wall and be visible from the outside of the colon during the resection surgery. This technique was reported by Jeffrey Ponsky, M.D., in 1975 in Endoscopic Marking of Colonic Lesions, 22 Gastrointestinal Endoscopy page 42, who used an Olympus NM-IK injection catheter to inject India ink and water into the mucosa of the colon. Therefore, such needles and tubes exist. The India ink marker is readily apparent on the serosal surface of the colon at a later laparotomy. In fact, Dr. Ponsky states it can be seen up to three weeks later. Dr. J. B. Poulard in Pre-operative Tattooing of Polypectomy Site, 17 Endoscopy 84 (1985) 1975, did the same thing also using an Olympus needle. He operated the next day and the India ink was readily apparent. Finally, in Localization of the Colonic Polypectomy Site 262 JAMA 2748 (Nov. 17, 1989), Dr. Angelo E. Gagardi of UCLA School of Medicine is asked how to localize a polypectomy site. He mentions tattooing the polypectomy site with India ink as a method for localizing the site. He states the stain may persist for longer than a month. However all such methods of employing a need to inject dye to localize a polypectomy site are inherently dangerous due the danger of the needle perforating the colon.
A number of U.S. patents disclose a variety of endoscopic forceps and tools for applying clips with penetrating teeth and large surface areas. U.S. Pat. No. 3,791,387 discloses a cutting snare forceps for excision and removal of polyps. A first wire extending through a rod as a snare may be retracted to severe a polyp. A second wire extends through the rod and attaches perpendicular to the first wire and when retracted serves to retain the severed polyp. U.S. Pat. No. 3,739,784 discloses a similar forceps but instead a wire may be adjacent to a blade. As the wire is retracted, the polyp is forced against the blade and thereby severed.
U.S. Pat. No. 3,828,790 discloses a surgical snare for polypectomies. The core of the snare is partially covered by a conductive wire presented as a spiral sleeve. The polyp is grasped with a snare with more control and decreased likelihood of accidental severing.
U.S. Pat. No. 2,571,908 discloses a surgical forceps in which the forceps when closed defines a chamber into which a severed mass of body tissue may be retained after cutting. U.S. Pat. No. 3,483,859 discloses a mechanism for marking a particular location of a body cavity, consisting of a string having an inflatable envelope thereon. A patient may swallow the device and then air may be pumped into the inflatable envelope. The exterior of the envelope contains an absorbent material which will absorb blood which may be located in an adjacent area. After the device is removed, the location of blood in the esophagus may be discerned by examining the envelope. However, internal tissue is not itself marked by this procedure.